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As the new car market shifts towards small-displacement turbocharged engines, big, brutish engines are becoming rarer. Not only are humdrum midsize sedans downsizing their engines, supercars are too: The Ferrari 458 Italia has a 4.5-liter V-8, while the McLaren 12C has an even smaller 3.8-liter V-8. But not all is lost, and for those who still believe there’s no replacement for displacement, here are the Top 10 largest engines you can get in the U.S.

You know you’re in for a good time when a Lamborghini Aventador has the smallest engine on your list. With just 6.5 liters of displacement, the Aventador’s naturally aspirated V-12 makes 691 hp and 509 lb-ft of torque. That makes it the smallest and second-most-powerful engine on this list. We’re off to a good start already, aren’t we?

“High-rpm power is immense to say the least, and midrange torque seems almost superfluous — until, that is, you remember that excess can be a really good thing. Whether speeds are double or triple digits, the engine pulls, and pulls strongly. And the soundtrack — deep, operatic, mechanized euphony — is music that never gets old.” – executive editor Ron Kiino

The 6.6-liter twin-turbo V-12 powerplant under the hood of the Rolls-Royce Ghost sedan and Wraith coupe might wear the badge of the storied British automaker, but the engine is BMW born and bred.

“Like every great Rolls-Royce engine, the Ghost’s V-12 is a paragon of effortless motion, uncannily smooth and silent. It is also very potent, with 536 hp and 575 lb.-ft. of torque on tap from just 1500 rpm, turning the Ghost into a leather-lined cruise missile capable of sprinting from 0 to 60 mph in 4.3 seconds.” – editor-at-large Angus MacKenzie

The U.S. still knows how to make a big V-8. The Chevy Silverado and GMC Sierra HD both earn their spots on this list thanks to their 6.6-liter turbodiesel V-8s paired with Allison transmissions. The combo is so good, we named the diesel-powered Silverado HD our Truck of the Year in 2011.

The Ford Super Duty’s Powerstroke 6.7-liter turbodiesel V-8 isn’t the largest of the heavy duty pickups, but its eight cylinders not only churn out more horsepower than its Detroit rivals, but also make a jaw-dropping 800 lb-ft of torque.

“The engineers designed the engine layout to make it easier to manage noise and vibration, and the result of their work is an engine that is incredibly quiet; as has been the industry trend for the last couple of years, this is a modern diesel, one you can’t hear from a distance and doesn’t fill the cabin with noise. Yet it’s also much more powerful than before, making the Super Duty pull away from traffic lights like a heavy-duty hot rod.” – associate editor/Truck Trend editor Allyson Harwood

In full-size heavy-duty trucks, torque is king. No truck offers more torque than the 850 lb-ft of twist available in the Ram HD lineup. That isn’t why the Ram earned a spot on this list; its Cummins-sourced 6.7-liter turbodiesel makes it the sixth-largest engine available in the U.S., while its straight-six configuration gives it the lowest cylinder count here, along with the second-best torque figure.

“For 2012, Ram has upped its game, introducing the new upscale Laramie Longhorn trim package and a new high-output engine package that brings torque up to a simply staggering 800 lb-ft and includes an uprated torque converter. Those facts and figures all sound mighty impressive, but do they really make the Ram a barnstormer when the rubber meets the road? When it came to our standard performance testing, the answer was a resounding ‘no.'” – associate editor Rory Jurnecka

Owners might think of the Bentley Mulsanne as British steel, but like the Rolls-Royces on this list, the flagship luxury sedan was built with the help of Germans. That doesn’t change the fact that the Mulsanne has the fifth-largest largest engine in the U.S. in the form of its 6.7-liter twin-turbo V-8 – though make sure you don’t let Bentley upsell it as a 6.75-liter unit.

“[This new Mulsanne’s] 6.75-liter twin-turbo V-8 produces 752 lb-ft of torque at 1500 rpm. With the exception of a few heavy-duty diesels, the only production car that offers more twist is the 16-cylinder, quad-turbo Veyron…In fact, there’s so much low-down torque that our road test editor, Scott Mortara, kept insisting the Mulsanne is a diesel. For those who care, the torque-monster engine also produces 505 horsepower. Bentley’s latest and greatest flows off the line like a redwood caught in a flash flood. There’s simply no stopping it.” – senior features editor Jonny Lieberman

4. Rolls-Royce Phantom: 6.7-liter, 453-hp and 531 lb-ft V-12 (6789cc)

There’s an old automotive urban legend that Rolls-Royce refused to publish engine specs, and instead just simply described power output as “adequate.” The Phantom’s big 6.7-liter V-12’s 453 hp most certainly fits that description.

“The whole time I was behind the wheel, I felt like a chauffeur. Which, I suppose, is the entire point…if a fortress of solitude is what you’re after, think Phantom Saloon, though driving-wise there’s not much difference between the new one and the old. The direct-injected 6.75-liter V-12 remains the same. Power is still ‘adequate.’ So much so that no one from Rolls mentioned the power output even once (if you’re boorish enough to ask, 453 horsepower and 531 lb-ft of torque).” – senior features editor Jonny Lieberman

To say that the LS7 in the Corvette Z06 and 427 and upcoming Camaro Z/28 is one of our favorite engines would be an understatement. The big pushrod V-8 displaces 7.0 liters and easily churns out 505 hp and 470 lb-ft of torque without any fancy turbo- or superchargers. The LS7 is a glorious engine, with power always on tap and the mightiest of V-8 bellows.

“On the street, the 427 feels every bit as monstrous as the Z06. The raw power of the LS7 seems endless, and running up to its 7000-rpm redline is just asking for a visit with Johnny Law. It really is a shame that the valves in the mufflers don’t open until you’re over 3000 rpm and standing on it, because you’ll only hear that glorious engine note for a second before you’re in felony territory.” – associate editor Scott Evans

Well look at that — a top 10 list that the Bugatti Veyron doesn’t top. Though its quad-turbo W-16 has the most turbos and cylinders by far, the mammoth 1200-hp engine is just 0.4 liters (just more than a can of beer) shy of earning the top spot. We doubt Bugatti is concerned; with a top speed of over 250 mph, does displacement really matter?

“Once underway, the monstrous pull never stops — and I mean never. I have felt powerful cars run out of both breath and gears, or into the invisible wall of drag, but I never felt the slightest twinge of such weakness in the Super Sport. At speeds that start to bleed momentum from less-super cars, the Bugatti feels invincible, limitless. In fact there are few roads in the world upon which mere mortals can drive that can even begin to tax this (or any) Veyron’s potential.” – editor-in-chief Edward Loh

1. SRT Viper: 8.4-liter, 640-hp and 600 lb-ft V-10

The biggest engine available in the U.S. belongs to an American supercar — and all remains right in the world. The Viper’s 8.4-liter V-10 makes an impressive 640 hp and 600 lb-ft of torque. In track-ready Viper TA form, the combo is enough to allow the brute to snake its way to the top of Mazda Raceway Laguna Seca’s lap board, making it the fastest production car around the storied racetrack.

“The Viper still has an 8.4-liter V-10 now spitting out 640 horses and 600 lb-ft of torque, the latter of which isn’t available until 5000 rpm, aka when all hell has already broken loose.” – senior features editor Jonny Lieberman

And there you have it: the 10 largest engines you can get in the U.S. of A. Which engine is your favorite? Sound off in the comments below.